Impact-resistant cyclic olefin based resin composition and mouldings

ABSTRACT

A cyclic olefin based resin composition which includes: a cyclic olefin based resin (A); a modified cyclic olefin based resin (B) prepared by grafting and/or copolymerizing an unsaturated carboxylic acid or an unsaturated carboxylic acid anhydride to the cyclic olefin based resin (A); an olefinic elastomer (C); and a modified polyolefin (D) having an epoxy group, and in which a weight ratio of the component A to the component B, i.e. A/B, is in the range of 98/2 to 2/98, a weight ratio of the component C to the component D, i.e. C/D, is in the range of 98/2 to 2/98, and a ratio of the total weight of components A and B to the total weight of components C and D, i.e. (A+B)/(C+D), is in the range of 95/5 to 50/50. A molding composed of the cyclic olefin based resin composition is excellent in impact resistance, resistance to flaking off, and the like.

TECHNICAL FIELD

The present invention relates to a cyclic olefin based resin compositionwhich contains a cyclic olefin based resin, a modified cyclic olefinbased resin prepared by grafting an unsaturated carboxylic acid or anunsaturated carboxylic acid anhydride to the cyclic olefin based resin,an olefinic elastomer, and a modified polyolefin having an epoxy group,and a molding thereof. The molding of the cyclic olefin based resincomposition of the present invention is excellent in impact resistance,resistance to flaking off, and the like.

BACKGROUND ART

Cyclic olefin based resins are amorphous and thermoplastic olefin basedresins each having a cyclic olefin skeleton in its backbone, areexcellent in transparency, low birefringence, heat resistance, lightweight property, dimensional stability, low water absorption,hydrolyzability resistance, and chemical resistance, and each includecharacteristics such as a low dielectric constant, low dielectric loss,and no inclusion of environmental load substances.

Thus, the cyclic olefin based resins have been used for widely intendedpurposes including: medicine related instruments such as prefilledsyringes, and containers and stopper cocks for infusions; high frequencyelectronic parts; and packages and containers of chemicals and foods aswell as optical uses such as optical discs, lenses, and opticalwaveguides.

However, application ranges of the cyclic olefin based resins arelimited because the resins are inferior in impact resistance. Efforts toimprove the impact resistance of cyclic olefin based resins and toextend the intended uses thereof have been ever made.

For example, JP 01-163236 A proposes a cyclic olefin based resincomposition with high impact resistance where an olefinic elastomer iscombined to a cyclic olefin based resin. However, the olefinic elastomeris extremely effective for improving the impact resistance but isinferior in affinity with the cyclic olefin based resin, and there is adrawback in that the surface of a molding of the composition flakes off.

JP 01-256548 A proposes a cyclic olefin based resin composition withhigh impact resistance where a styrenic elastomer is combined to acyclic olefin based resin. Surface flaking is difficult to occur on amolding of the composition because the styrenic elastomer has a highaffinity with the cyclic olefin based resin, but the styrenic elastomeris inferior in improvement effect on impact resistance to the olefinicelastomer.

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide a cyclic olefin basedresin composition for moldings which are excellent in impact resistance,resistance to surface flaking off, and the like.

As a result of the study, the inventors of the present invention havefound a method of effectively improving impact resistance whilepreventing the surface of moldings from flaking off by using a cyclicolefin based resin composition where a cyclic olefin based resin (A), amodified cyclic olefin based resin (B) prepared by grafting anunsaturated carboxylic acid or an unsaturated carboxylic acid anhydride,an olefinic elastomer (C), and a modified polyolefin (D) having an epoxygroup are in a specified ratio, and the inventors have completed thepresent invention.

That is, according to a first aspect of the present invention, there isprovided a cyclic olefin based resin composition including:

-   -   a cyclic olefin based resin (A);    -   a modified cyclic olefin based resin (B) prepared by grafting        and/or copolymerizing an unsaturated carboxylic acid or an        unsaturated carboxylic acid anhydride to the cyclic olefin based        resin (A);    -   an olefinic elastomer (C); and    -   a modified polyolefin (D) having an epoxy group,    -   in which a weight ratio A/B of the component A to the component        B is in the range of 98/2 to 2/98,    -   a weight ratio C/D of the component C to the component D is in        the range of 98/2 to 2/98, and    -   a ratio (A+B)/(C+D) of the total weight of the component A and        the component B to the total weight of the component C and the        component D is in the range of 95/5 to 50/50.

According to a second aspect of the present invention, there is provideda cyclic olefin based resin composition according to the first aspect ofthe present invention, in which the component C is a copolymer ofethylene and an α-olefin.

According to a third aspect of the present invention, there is provideda cyclic olefin based resin composition according to the first or secondaspect of the present invention, in which the component D is a copolymerof ethylene and glycidyl (meth)acrylate.

According to a fourth aspect of the present invention, there is provideda cyclic olefin based resin composition according to any one of thefirst to third aspects of the present invention, in which the componentB is a modified cyclic olefin based resin which is obtained by a cyclicolefin based resin being grafted with (meth)acrylic acid or maleicanhydride.

According to a fifth aspect of the present invention, there is provideda cyclic olefin based resin composition according to any one of thefirst to fourth aspects of the present invention, in which a cyclicolefin based resin of the component A and a cyclic olefin based resinused as a base resin prior to modification in the component B areindependently a copolymer of ethylene and a cyclic olefin.

According to a sixth aspect of the present invention, there is provideda molding of cyclic olefin based resin obtained by injection molding,compression molding, injection compression molding, extrusion, or blowmolding of the cyclic olefin based resin composition according to anyone of the first to fifth aspects of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention is illustrated in detail.

(A) Cyclic Olefin Based Resin

A cyclic olefin based resin (A) (referred to as component A) is a highmolecular compound the backbone of which is made up of carbon-carbonbonds and which has a cyclic hydrocarbon structure in at least a part ofthe backbone. This cyclic hydrocarbon structure is introduced by usingas a monomer a compound (cyclic olefin) having at least one olefinicdouble bond in the cyclic hydrocarbon structure typified by norborneneor tetracyclododecene.

Cyclic olefin based resins (A) are classified into addition (co)polymersof cyclic olefins or hydrogenates thereof (A1), addition copolymers ofcyclic olefins and α-olefins or hydrogenates thereof (A2), andring-opening (co)polymers of cyclic olefins or hydrogenates thereof (A3)depending on methods of manufacturing the resins.

Specific examples of the above cyclic olefins include: monocyclicolefins such as cyclopentene, cyclohexene, cyclooctane, cyclopentadiene,and 1,3-cyclohexadiene; bicyclic olefins such asbicyclo[2.2.1]hepta-2-ene(conventional name: norbornene),5-methyl-bicyclo[2.2.1]hepta-2-ene,5,5-dimethyl-bicyclo[2.2.1]hepta-2-ene,5-ethyl-bicyclo[2.2.1]hepta-2-ene, 5-butyl-bicyclo[2.2.1]hepta-2-ene,5-ethylidene-bicyclo[2.2.1]hepta-2-ene,5-hexyl-bicyclo[2.2.1]hepta-2-ene, 5-octyl-bicyclo[2.2.1]hepta-2-ene,5-octadecyl-bicyclo[2.2.1]hepta-2-ene,5-methylidyne-bicyclo[2.2.1]hepta-2-ene,5-vinyl-bicyclo[2.2.1]hepta-2-ene, 5-propenyl-bicyclo[2.2.1]hepta-2-ene,5-methoxy-carbonyl-bicyclo[2.2.1]hepta-2-ene,5-cyano-bicyclo[2.2.1]hepta-2-ene,5-methyl-5-methoxycarbonyl-bicyclo[2.2.1]hepta-2-ene,5-methoxycarbonylbicyclo[2.2.1]hepta-2-ene,5-ethoxycarbonylbicyclo[2.2.1]hepta-2-ene,5-methyl-5-methoxycarbonylbicyclo[2.2.1]hepta-2-ene,5-methyl-5-ethoxycarbonylbicyclo[2.2.1]hepta-2-ene,bicyclo[2.2.1]hepta-5-enyl-2-methylpropionate,bicyclo[2.2.1]hepta-5-enyl-2-methyloctanate,bicyclo[2.2.1]hepta-2-ene-5,6-dicarboxylic acid anhydride,5-hydroxymethylbicyclo[2.2.1]hepta-2-ene,5,6-di(hydroxymethyl)bicyclo[2.2.1]hepta-2-ene,5-hydroxy-1-propylbicyclo[2.2.1]hepta-2-ene,5,6-dicarboxybicyclo[2.2.1]hepta-2-ene,5-cyanobicyclo[2.2.1]hepta-2-ene, andbicyclo[2.2.1]hepta-2-ene-5,6-dicarboxylic acid imide; tricyclic olefinssuch as tricyclo[4.3.0.1^(2,5)]deca-3,7-diene(conventional name:dicyclopentadiene), tricyclo[4.3.0.1^(2,5)]deca-3-ene,tricyclo[4.4.0.1^(2,5)]undeca-3,7-diene ortricyclo[4.4.0.1^(2,5)]undeca-3,8-diene and a partly hydrogenatedproduct thereof (or an adduct of cyclopentadiene and cylohexene),tricyclo[4.4.0.1^(2,5)]undeca-3-ene,5-cyclopentyl-bicyclo[2.2.1]hepta-2-ene,5-cyclohexyl-bicyclo[2.2.1]hepta-2-ene,5-cyclohexenylbicyclo[2.2.1]hepta-2-ene, and5-phenyl-bicyclo[2.2.1]hepta-2-ene; tetracyclic olefins such astetracyclo[4.4.0.1^(2,5).1^(7,10)]dodeca-3-ene (also simply referred toas tetracyclododecene),8-methyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodeca-3-ene,8-ethyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodeca-3-ene,8-methylidenetetracyclo[4.4.0.1^(2,5).1^(7,10)] dodeca-3-ene,8-ethylidenetetracyclo[4.4.0.1^(2,5).1^(7,10)]dodeca-3-ene,8-vinyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodeca-3-ene,8-propenyl-tetracyclo[4.4.0.1^(2,5).1^(7,10)]dodeca-3-ene,8-methoxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)] dodeca-3-ene,8-methyl-8-methoxycarbonyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodeca-3-ene,8-hydroxymethyltetracyclo[4.4.0.1^(2,5).1^(7,10)]dodeca-3-ene, and8-carboxytetracyclo[4.4.0.1^(2,5).1^(7,10)]dodeca-3-ene; polycyclicolefins such as8-cyclopentyl-tetracyclo[4.4.0.1^(2,5).1^(7,10)]dodeca-3-ene,8-cyclohexyl-tetracyclo[4.4.0.1^(2,5).1^(7,10)]dodeca-3-ene,8-cyclohexenyl-tetracyclo[4.4.0.1^(2,5).1^(7,10)]dodeca-3-ene,8-phenyl-cyclopentyl-tetracyclo[4.4.0.1^(2,5).1^(7,10)]dodeca-3-ene,tetracyclo[7.4.1^(3,6).0^(1,9).0^(2,7)]tetradeca-4,9,11,13-tetraene(also referred to as1,4-methano-1,4,4a,9a-tetrahydrofluorene),tetracyclo[8.4.1.^(4,7)0^(1,10).0^(3,8)]pentadeca-5,10,12,14-tetraene(also referred to as1,4-methano-1,4,4a,5,10,10a-hexahydroanthracene),pentacyclo[6.6.1.1^(3,6).0^(2,7).0^(9,14) ]-4-hexadecene,pentacyclo[6.5.1.1^(3,6).0^(2,7).0^(9,13)]-4-pentadecene,pentacyclo[7.4.0.0^(2,7).1^(3,6).1^(10,13)]-4-pentadecene,heptacyclo[8.7.0.1^(2,9).1^(4,7).1^(11,17).0^(3,8).0^(12,16)]-5-eicosene,heptacyclo[8.7.0.1^(2,9).0^(3,8).1^(4,7).0^(12,17).1^(13,16)]-14-eicosene,and a cyclopentadiene tetramer. The above cyclic olefins may be usedsingly or two or more of them may be used in combination.

Specific examples of α-olefins that may copolymerize with cyclic olefinsinclude ethylene and α-olefins each having 2 to 20, preferably 2 to 8carbon atoms such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene,3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene,3-ethyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-pentene,4,4-dimethyl-1-hexene, 3-ethyl-1-hexene, 4-ethyl-1-hexene, 1-octene,1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and1-eicosene. The above α-olefins may be used singly or two or more ofthem may be used in combination.

Polymerization methods for the cyclic olefin or for the cyclic olefinand an α-olefin, and methods of hydrogenating the resultant polymers arenot particularly limited, and the hydrogenation can be performedaccording to methods known in the art.

Of the cyclic olefin based resins (A) exemplified above, the additioncopolymers of cyclic olefins and α-olefins or hydrogenates thereof (A2)are particularly preferable because a balance between properties andcosts is kept.

The cyclic olefin based resins are industrially available ascommercially available articles such as brands names, Topas (suppliedfrom Ticona GmbH), Apel (supplied from Mitsui Chemical Co., Ltd.),Zeonex (supplied from Zeon Corporation), Zeonor (supplied from ZeonCorporation), and Arton (supplied from JSR Corporation).

(B) Modified Cyclic Olefin Based Resin

A modified cyclic olefin based resin (B) (referred to as component B) isone modified by grafting and/or copolymerizing an unsaturated carboxylicacid or an unsaturated carboxylic acid anhydride (uc) to one of or amixture of two or more of the cyclic olefin based resins (A) describedabove. The cyclic olefin based resin (A) used for the component B beforethe modification and the cyclic olefin based resin (A) as the componentA may be the same or different.

(uc) Unsaturated Carboxylic Acid or Unsaturated Carboxylic AcidAnhydride

The unsaturated carboxylic acid or unsaturated carboxylic acid anhydride(uc) (referred to as a component uc) used for modifying the component Bis an organic compound having one or more carboxyl groups or acidanhydride groups and having one or more ethylenic unsaturated bonds inthe molecule.

Examples of the unsaturated carboxylic acid in the component uc include:aliphatic unsaturated monocarboxylic acids such as (meth)acrylic acidand crotonic acid; aromatic unsaturated monocarboxylic acids such ascinnamic acid; aliphatic unsaturated dicarboxylic acids such as maleicacid, fumaric acid, itaconic acid, and citraconic acid; and monoestersof the aliphatic unsaturated dicarboxylic acids with aliphatic alcoholseach having 1 to 10 carbon atoms including monoester maleates such asmonomethyl maleate, monoethyl maleate, monobutyl maleate, monohexylmaleate, monooctyl maleate, and mono(2-ethylhexyl) maleate, andcorresponding monoester fumarates thereof. Of those, (meth)acrylic acid,maleic acid, and monoalkyl maleates are preferable as the unsaturatedcarboxylic acids. Examples of the unsaturated carboxylic acid anhydridein the component uc include maleic anhydride, itaconic anhydride,citraconic anhydride, and himic anhydride, of which maleic anhydride ispreferable. The above components uc may be used singly or two or more ofthem may be used in combination.

Modification of the cyclic olefin based resin is accomplished byreacting a component A and a component uc in the presence of a radicalgenerator and binding (grafting) the component uc to the component A.Alternatively, when the cyclic olefin based resin is synthesized bypolymerizing a monomer, the modified cyclic olefin based resin (B) maybe obtained by copolymerizing the above unsaturated carboxylic acid orthe unsaturated carboxylic acid anhydride (uc) with the cyclic olefin.

The radical generator is a compound which generates a free radical andhas a function as a polymerization initiator which initiates thepolymerization of a polymerizable compound, and an organic peroxide issuitably used as the radical generator.

Examples of the radical generator include: alkyl hydroperoxides such ast-butyl hydroperoxide, p-menthane hydroperoxide, cumene hydroperoxide,diisopropylbenzene hydroperoxide, and2,5-dimethylhexane-2,5-dihydroperoxide; dialkyl peroxides such asdi-t-butyl peroxide, t-butylcumyl peroxide, t-butylperoxycumene, dicumylperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane,2,5-dimethyl-2,5-di(t-butylperoxy)hexene-3, andα,α′-bis(t-butylperoxy-m-isopropyl)benzene; diacyl peroxides such asbenzoyl peroxide, lauroyl peroxide, and p-chlorobenzoyl peroxide;alkylidene peroxides such as methyl ethyl ketone peroxide,1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, and1,1-bis(t-butylperoxy)cyclododecane; and peracid esters such asn-butyl-4,4-bis(t-butylperoxy)valerate and t-butylperoxybenzoate.

A graft reaction can be performed by kneading the component A, thecomponent uc, and the radical generator in melting states or bydissolving them in an appropriate solvent and mixing and heating thesolution, but industrially the method of mixing in the melting states issuitable because of its high productivity.

For melting and kneading, kneading machines commonly used such as anextruder, Brabender, kneader, Banbury mixer, and roll mixer can beutilized, and particularly a closed type apparatus such as an extruderor kneader is preferable. A kneading temperature can be selected fromthe range of a melting temperature to a decomposing temperature of thecomponent A used, and for example is a temperature which is 30 to 200°C. higher than a glass transition temperature (Tg) of the component A. Akneading time period is for example from 20 sec to 1 hour, preferablyfrom about 30 sec to 30 min, and frequently from about 30 sec to 10 min.

A use amount of the component uc used for the modification is dependenton a type of the component, but is approximately from 0.1 to 20 parts byweight and preferably from 0.5 to 10 parts by weight based on 100 partsby weight of the component A which is a base resin. An excessively smalluse amount of the component uc is not preferable because the desiredphysical properties of the composition according to the presentinvention such as prevention of flaking off are not accomplished. Anexcessively large use amount of the component uc is not preferablebecause an amount of unreacted compounds in the modified cyclic olefinbased resin (B) becomes too large, and thus various adverse effects onthe composition occur, which include exudation of the unreactedcompounds, reduction of mechanical strength, and nasty odor at molding.

A use amount of the radical generator is dependent on types of thecomponent A, the component uc, and the radical generator used, but isapproximately from 0.01 to 5 parts by weight and preferably from 0.1 to2 parts by weight based on 100 parts by weight of the total amount ofthe component A and the component uc. An excessively small use amount ofthe radical generator is not preferable because efficiency of a graftreaction is low, and thus the amount of carboxylic acid or acidanhydride which is not bound to the cyclic olefin based resin becomeslarge. An excessively large addition amount of the radical generator isnot preferable because a crosslinking reaction of the cyclic olefinbased resin occurs to coagulate the resin, thereby making it impossibleto mix with the other components which compose the composition of thepresent invention.

A number average molecular weight of the modified cyclic olefin basedresin (B) is from 1000 to 1,000,000, and preferably from 10,000 to100,000.

(C) Olefinic Elastomer

An olefinic elastomer (C) (referred to as component C) according to thepresent invention is a soft polymer exclusively composed of carbon andhydrogen atoms and having no aromatic ring. Examples of the component Cinclude: α-olefin copolymers such as copolymers of ethylene, propylene,1-butene, and 1-octene; diene (such as butadiene and isoprene) basedpolymers; and copolymers of α-olefins and dienes. α-olefin copolymershave high heat resistance stability and thus are suitable because theyhave no unsaturated bonds in their molecules. Examples of the α-olefincopolymers include ethylene-propylene copolymers, ethylene-butetecopolymers, and ethylene-octene copolymers.

For hardness of the olefinic elastomer (C), Shore A hardness is 95 orless, and preferably 85 or less.

(D) Modified Polyolefin Having an Epoxy Group

A modified polyolefin (D) (referred to as component D) having an epoxygroup according to the present invention is a polymer the backbone ofwhich is made up of carbon-carbon bonds and which has no aromatic ringin the backbone and has an epoxy group in its side chain. Specifically,copolymers of an unsaturated epoxy compound (ue) and an α-olefin and amodified polyolefin prepared by grafting the unsaturated epoxy compound(ue) to polyolefin are exemplified.

(ue)Unsaturated Epoxy Compound

An unsaturated epoxy compound (ue) (referred to as component ue) is anorganic compound containing one or more ethylenic unsaturated bonds andone or more epoxy groups within its molecule. Examples of theunsaturated epoxy compound (ue) include: unsaturated glycidyl etherssuch as allylglycidyl ether, and chalcone glycidyl ether; glycidylesters and epoxyesters such as glycidyl (meth)acrylate, vinylbenzoicglycidyl ester, allylbenzoic glycidyl ester, cinnamate glycidyl ester,cinnamylidene acetic acid glycidyl ester, dimer acid glycidyl ester, andesters of epoxydized stearyl alcohol and (meth)acrylic acid; andepoxydized unsaturated chained and cyclic olefins such as epoxyhexene,and limonene oxide. In particular, a glycidyl ether or glycidyl esterwith a (meth)acryloyl group is preferable.

Examples of an α-olefin copolymerized with the component ue includeα-olefins each having 2 to 10 carbons such as ethylene, propylene,butene, hexene, and octene.

The copolymer of the component ue and the α-olefin which is onerepresentative example of the component (D) is obtained bycopolymerizing one or two or more of the components ue and one or two ormore of α-olefins. Examples of the copolymer include anethylene-glycidyl (meth)acrylate copolymer, ethylene-propylene-glycidyl(meth)acrylate copolymer, and ethylene-octene-glycidyl (meth)acrylatecopolymer. In particular, the ethylene-glycidyl (meth)acrylate copolymeris easily available industrially and suitable.

A copolymerized amount of the component ue in the copolymer of thecomponent ue and the α-olefin is dependent on types of the component ueand the α-olefin used, but is typically from 0.1 to 30% by weight, andpreferably from 1 to 15% by weight. An excessively small copolymerizedamount of the component ue is not preferable because the desiredphysical properties of the composition according to the presentinvention such as prevention of flaking off are not accomplished. Anexcessively large copolymerized amount of the component ue is notpreferable because cost of the copolymer becomes high.

For a modified polyolefin which is another representative example of thecomponent D, an unsaturated group is grafted to polyolefin to produce amodified polyolefin having an epoxy group by reacting an unsaturatedepoxy compound (ue) and polyolefin in the presence of a radicalgenerator using the similar method to the method of manufacturing themodified cyclic olefin based resin (B) previously shown.

Examples of polyolefin which becomes a base of the above modifiedpolyolefin include: homopolymers or copolymers of α-olefins such asethylene, propylene, 1-butene, and 1-octene; diene (such as butadieneand isoprene) based polymers; and copolymers of α-olefins and dienes.

Polyolefin which becomes the base of the modified polyolefin may be thesame as or different from the olefinic elastomer (C), but it ispreferred that they be the same.

A use amount of the component ue used for the graft reaction isdependent on the type of the component ue, but is approximately from 0.1to 20 parts by weight, and preferably from 0.5 to 10 parts by weightbased on 100 parts by weight of the polyolefin which is the base resin.An excessively small use amount of the component ue is not preferablebecause the desired physical properties of the composition according tothe present invention such as prevention of flaking off are notaccomplished. An excessively large use amount of the component ue is notpreferable because the amount of the component ue which is not bound topolyolefin becomes too large, and thus various adverse effects on thecomposition occur, which include exudation, reduction of mechanicalstrength, and nasty odor at molding.

The use amount of the radical generator added at the graft reaction isdependent on types of the polyolefin, the component ue, and the radicalgenerator used, but is approximately from 0.01 to 5 parts by weight, andpreferably from 0.1 to 2 parts by weight based on 100 parts by weight ofthe total amount of the polyolefin and the component ue. An excessivelysmall use amount of the radical generator is not preferable becauseefficiency of the graft reaction is low, and thus the amount of thecomponent ue which is not bound to polyolefin becomes large. Anexcessively large addition amount of the radical generator is notpreferable because the crosslinking reaction of the polyolefin occurs tocoagulate the polyolefin, thereby-making it impossible to mix with theother components which compose the composition of the present invention.

The construction ratio of each component which constructs thecomposition of the present invention is as follows. The weight ratio A/Bof the component A to the component B is in the range of 98/2 to 2/98and preferably 98/2 to 50/50. The weight ratio C/D of the component C tothe component D is in the range of 98/2 to 2/98 and preferably 98/2 to50/50. Further, the ratio (A+B)/(C+D) of the total weight of thecomponent A and the component B to the total weight of the component Cand the component D is in the range of 95/5 to 50/50, and preferably90/10 to 60/40.

The other thermoplastic resins (f), inorganic or organic fillers (g),various compounding agents (h), and the like can be added to the cyclicolefin based resin composition if necessary in the range where theproperties of the cyclic olefin based resin composition are notimpaired.

Examples of the other thermoplastic resins (f) include: polyphenylenesulfide; polyphenylene ether; polyether sulfone; polysulfone;polycarbonate; polyacetal; polyester based polymers such as a liquidcrystal polymer, aromatic polyester, polyallylate, polyethyleneterephthalate, and polybutylene terephthalate; polyolefin based polymerssuch as polyethylene, polypropylene, and poly4-methylpentene-1;polyamide based polymers such as nylon 6, nylon 66, and aromatic nylon;polymethyl methacrylate; polyacrylonitrilestyrene (AS resin); andpolystyrene.

Out of the above inorganic or organic fillers (g), examples of theinorganic fillers include, but are not particularly limited to: calciumcarbonate powder such as precipitated calcium carbonate light, calciumcarbonate heavy or pulverized calcium carbonate, and special calciumtype fillers; monchique fine powder; clays such as montmorillonite andbentonite and clays (aluminium silicate powder) such as fired clay andsilane modified clay; talc; silica (silicon dioxide) powder such asmelted silica and crystal silica; silicate-containing compounds such asdiatom earth and silica sand; natural minerals such as pumice stonepowder, slate powder, mica, micaceous powder, and asbestos, andpulverized articles thereof; alumina-containing compounds such asalumina, alumina colloid (alumina sol), alumina white, and aluminiumsulfate; minerals such as barium sulfate, lithopone, calcium sulfate,molybdenum disulfide, and graphite (black lead); glass type fillers suchas glass beads, glass flakes, and foam glass beads; fly ash spheres,volcanic glass hollow body, pumice stone balloon, synthetic inorganichollow body, carbon hollow body; anthracite culm, artificial ice stone(cryolite), titanium oxide, magnesium oxide, basic magnesium carbonate,dolomite, potassium titanate, monocrystal potassium titanate, calciumsulfite, calcium silicate, aluminium powder, molybdenum sulfide; glassfibers, carbon fibers, boron fibers, and silicon carbide.

Out of the above inorganic or organic fillers (g), examples of theorganic fillers include polyethylene fibers, polypropylene fibers,polyester fibers, polyamide fibers, fluorine fibers, ebonite powder,thermosetting resin hollow spheres, thermosetting resin fillers, epoxyresin fillers, silicone type fillers, saran hollow spheres, shellac,wood flour, cork powder, polyvinyl alcohol fibers, cellulose powder, andwood pulp.

The above various compounding agents (h) are not particularly limited solong as they are typically used as thermoplastic resin materials, andexamples thereof include compounding agents such as an anti-oxidant,ultraviolet ray absorber, light stabilizer, plasticizer, lubricant,anti-static agent, fire retardant, coloring agent such as a dye orpigment, near infrared ray absorber, and fluorescent brightening agent.

The cyclic olefin based resin composition of the present invention isprepared by mixing the above ingredients according to needs. A method ofmixing is not particularly limited so long as it is the method by whichthose ingredients are thoroughly dispersed. For example, there are amethod of kneading in a melted state with a mixer, biaxial kneader,roll, Brabender, monoaxial or biaxial extruder, or the like and a methodof dissolving compounding agents in an appropriate solvent to dispersethe compounding agents followed by eliminating the solvent bycoagulation, a cast method, or a direct drying method.

In particular, a method of kneading in a melted state followed byextruding into a stick shape using an extruder and cutting the stickinto an appropriate length to make a pellet is high in productivity andsuitable. A temperature at melting and kneading varies depending on thetype of the cyclic olefin based resin used, but is typically from 100 to400° C., and preferably from 200 to 350° C.

For the cyclic olefin based resin composition of the present invention,a molding can be obtained as it is and preferably as the above pelletshape by injection molding, injection compression molding, compressionmolding, extrusion molding, blow molding, or the like.

EXAMPLES

Hereinafter, the present invention is specifically illustrated by way ofexamples, but the present invention is not limited thereto.

Physical properties of compositions in Examples and Comparative Exampleswere evaluated as follows. Charpy impact strength: It was measuredaccording to JIS K7111. Surface flaking off of molding: the presence orabsence of flaking off was visually determined using No. 1 test pieceused for a tensile test, or the evaluation was performed by a cross cuttape test.

Visual Evaluation

∘: no flaking off was observed;

×: flaking off was widely observed;

N/A: no test was done.

Cross cut tape test: The evaluation was performed according to the testmethod described in JIS K5400-85.2. That is, a total of 100 grid-likecuts with 10 lanes in vertical and horizontal directions, respectivelyat 1 mm intervals were formed using a cutter knife on a grip portion ofthe test piece, commercially available Scotch tape was attached, andthis tape was quickly peeled off. The number of remaining grids whichwere not peeled off among 100 grids was rendered as an index of easinessfor surface flaking off. A larger number of the remaining grids whichwere not peeled off means that the grids are more difficult to flakeoff. In the case of no flaking off, the value becomes 100.

The components A, B. C, and D used in Examples and Comparative Examplesare as follows.

Cyclic Olefin Based Resin (A)

Cyclic olefin based resin A1: Topas 6017 (supplied from Ticona, additioncopolymer of norbornene and ethylene, glass transition temperature 174°C.)

Cyclic olefin based resin A2: Topas 6015 (supplied from Ticona, additioncopolymer of norbornene and ethylene, glass transition temperature 160°C.)

Cyclic olefin based resin A3: APL 6015T (supplied from Mitsui Chemicals,addition copolymer of tetracyclododecene and ethylene, glass transitiontemperature 150° C.)

Cyclic olefin based resin A4: Zeonor 1600R (supplied from Nippon Zeon,hydrogenated product of norbornene based cyclic olefin ring openingpolymer, glass transition temperature 165° C.)

Note that the glass transition temperature was measured with adifferential scanning calorimeter (DSC) at a rate of temperatureincrease of 20° C./min.

Cyclic Olefin for Manufacturing Modified Cyclic Olefin Based Resin B

Topas 5013 (supplied from Ticona, addition copolymer of norbornene andethylene, glass transition temperature 137° C.)

APL 6013T (supplied from Mitsui Chemicals, addition copolymer oftetracyclododecene and ethylene, glass transition temperature 130° C.)

Zeonor 1420R (supplied from Nippon Zeon, hydrogenated product ofnorbornene based cyclic olefin ring opening polymer, glass transitiontemperature 138° C.)

Modified Cyclic Olefin Based Resin (B)

Reference Example 1 Synthesis of Modified Cyclic Olefin Based Resin B1

Precedently mixed with 100 parts by weight of cyclic olefin based resin,Topas 5013 were 2 parts by weight of acrylic acid as an unsaturatedcarboxylic acid and 0.4 parts by weight of2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3 (trade name: Perhexyne 25B(supplied from NOF corporation)) as a radical generator, and a graftreaction was performed by melting and kneading the mixture at a cylindertemperature of 200° C. using a 30 mm biaxial extruder to yield amodified cyclic olefin based resin B1.

Reference Example 2 Synthesis of Modified Cyclic Olefin Based Resin B2

A modified cyclic olefin based resin B2 was obtained in the totally samemanner as in Reference Example 1 except for using 0.4 parts by weight ofα,α′-bis(t-butylperoxy-m-isopropyl)benzene (trade name: Perbutyl P(supplied from NOF corporation)) as a radical generator.

Reference Example 3 Synthesis of Modified Cyclic Olefin Based Resin B3

A modified cyclic olefin based resin B3 was obtained in the totally samemanner as in Reference Example 1 except for using 2.7 parts by weight ofmaleic anhydride serving as an unsaturated carboxylic acid anhydrideinstead of 2 parts by weight of acrylic acid.

Reference Example 4 Synthesis of Modified Cyclic Olefin Based Resin B4

A modified cyclic olefin based resin B4 was obtained in the totally samemanner as in Reference Example 1 except for using APL 6013T as a cyclicolefin based resin.

Reference Example 5 Synthesis of Modified Cyclic Olefin Based Resin B5

A modified cyclic olefin based resin B5 was obtained in the totally samemanner as in Reference Example 1 except for using Zeonor 1420R as acyclic olefin based resin.

Olefinic Elastomer (C) and Styrenic Elastomer

Olefinic elastomer C1: ethylene-octene copolymer (supplied from DuPontDow Elastomers, Engage 8150, Shore hardness A75)

Olefinic elastomer C2: ethylene-propylene copolymer (supplied fromMitsui Chemicals, Tafmer-A-4085, Shore hardness A83)

The following styrenic elastomers were used for comparison.

Styrenic elastomer C3: styrene-ethylene-butylene-styrene block copolymer(styrene volume 29% by weight, supplied from Kraton Polymer, KratonG1652, Shore hardness A75) Styrenic elastomer C4:styrene-ethylene-butylene-styrene block copolymer (styrene volume 13% byweight, supplied from Kraton Polymer, Kraton G1657, Shore hardness A65)

Modified Polyolefin Having an Epoxy Group (D)

Modified polyolefin D1: ethylene-glycidyl methacrylate copolymer (tradename: Rex Pearl RA 4100 supplied from Nippon Petrochemicals Co., Ltd.)

Reference Example 6 Synthesis of Modified Polyolefin D2

Precedently mixed with 100 parts by weight of olefinic elastomer C1 were2 parts by weight of glycidyl acrylate as an unsaturated epoxy compoundand 0.4 parts by weight of 2,5-di(t-butylperoxy)hexyne-3 used inReference Example 1 as the radical generator, and a graft reaction wasperformed by melting and kneading the mixture at a cylinder temperatureof 200° C. using a 30 mm biaxial extruder to yield a modified polyolefinD2.

Comparative Example 1

Only the above cyclic olefin based resin A1 was injection-molded at acylinder temperature of 300° C. to make a test piece, and the test piecewas evaluated for Charpy impact strength. As a result, the Charpy impactstrength was as low as 1.0 J/m².

Comparative Examples 2 to 5

Improvement of impact strength was attempted by adding the aboveolefinic elastomer C1 or C2 or the styrenic elastomer C3 or C4 to thecyclic olefin based resin Al.

Precedently mixed with 70% by weight of the cyclic olefin based resin A1was 30% by weight of the above elastomer, and the mixture was melted andkneaded, and pelletized at a cylinder temperature of 300° C. using a 30mm biaxial extruder to yield compositions.

Those compositions were injection-molded at a cylinder temperature of300° C. to make test pieces, and the test pieces were evaluated forimpact strength and surface flaking off. The results are together shownin Table 1.

In the compositions each containing the olefinic elastomer, an impactimprovement effect is high whereas remarkable flaking off occurs(Comparative Example 2 or 3). In those each containing the styrenicelastomer with a styrene amount of 30%, there is no surface flaking offbut the impact improvement effect is small (Comparative Example 4). Whenusing a styrenic elastomer with less styrene amount, i.e., more rubbercomponent amount, the impact strength is improved but the effect thereofis smaller than that in the case of the olefinic elastomer. Furthermore,the surface flaking off occurs, which is not as bad as that in the caseof olefinic elastomer (Comparative Example 5). TABLE 1 ComparativeExample Unit 1 2 3 4 5 Constitution of composition Cyclic olefin basedwt % 100 70 70 70 70 resin A1 Olefinic elastomer C1 wt % 30 Olefinicelastomer C2 wt % 30 Styrenic elastomer C3 wt % 30 Styrenic elastomer C4wt % 30 Characteristics of composition Charpy impact kJ/m² 1.0 10.1 8.22.1 5.0 strength Surface flaking off Visual N/A X X ◯ X of moldingevaluation Cross cut tape test Number of N/A 54 42 100 93 remaininggrids

Examples 1 to 3 and Comparative Examples 6 and 7

The cyclic olefin based resin A1, the olefinic elastomer C1, themodified polyolefin D1, and the pellets of the modified olefin basedresin B1 manufactured in Reference Example 1 were precedently mixed inconstitutions shown in Table 2, and these mixtures were melted andkneaded, and pelletized at a cylinder temperature of 300° C. using a 30mm biaxial extruder to yield compositions. Those compositions wereinjection-molded at the cylinder temperature of 300° C. to make testpieces, and the test pieces were evaluated for impact strength andsurface flaking off. The results were shown in Table 2.

As is obvious from the results of Examples 1 to 3, the olefinicelastomer (C) is effective for the improvement of impact strength of thecyclic olefin based resin (A), but has a drawback of causing the surfaceflaking off. However, it is shown that the impact strength is improvedwithout causing the surface flaking off by the addition of the modifiedcyclic olefin based resin (B) and the modified polyolefin (D).

It is shown that even when only one of the component B and the componentD is added, the improvement of flaking off is observed but isinsufficient (Comparative Examples 6 and 7), and both the components arerequired for the improvement of flaking off. TABLE 2 Comparative ExampleExample Unit 6 7 1 2 3 Constitution of composition Cyclic olefin basedwt % 63 70 63 56 35 resin A1 Modified cyclic olefin wt % 7 7 14 35 basedresin B1 Olefinic elastomer C1 wt % 30 24 24 24 15 Modified polyolefinD1 wt % 6 6 6 15 (A + B)/(C + D) wt ratio 70/30 70/30 70/30 70/30 70/30A/B wt ratio 90/10 100/0 90/10 80/20 50/50 C/D wt ratio 100/0 80/2080/20 80/20 50/50 Characteristics of composition Charpy impact strengthkJ/m² 10.8 12.5 19.0 21.3 17.5 Surface flaking off of Visual X X ◯ ◯ ◯molding evaluation Cross cut tape test Number of 67 82 100 100 100remaining grids

Examples 4 to 7 and Comparative Examples 8 and 9

The results shown in Table 3 were obtained by making constitutions shownin Table 3, and performing the molding and the evaluation as is the casewith Example 1. Even when the content of the component C is from 20% to10%, flaking off of a molding occurs (Comparative Examples 8 and 9), butit is possible to eliminate the flaking off by adding the components Band D (Examples 4 to 7) TABLE 3 Comparative Example Example Unit 8 9 4 56 7 Constitution of composition Cyclic olefin based resin A1 wt % 80 9072 76 81 85.5 Modified cyclic olefin based wt % 8 4 9 4.5 resin B1Olefinic elastomer C1 wt % 20 10 16 18 8 9 Modified polyolefin D1 wt % 42 2 1 (A + B)/(C + D) wt ratio  80/20  90/10 80/20 80/20 90/10 90/10 A/Bwt ratio 100/0 100/0 90/10 95/5  90/10 95/5  C/D wt ratio 100/0 100/080/20 90/10 80/20 90/10 Characteristics of composition Charpy impactstrength kJ/m² 5.5 2.7 12.8 11.9 4.1 3.8 Surface flaking off of moldingVisual X X ◯ ◯ ◯ ◯ evaluation Cross cut tape test Number of 75 90 100100 100 100 remaining grids

[Examples 8 to 12

The results shown in Table 4 were obtained by making constitutions shownin Table 4, and performing the molding and the evaluation as is the casewith Example 1. TABLE 4 Example Unit 8 9 10 11 12 Constitution ofcomposition Cyclic olefin based wt % 63 56 63 63 63 resin A1 Modifiedcyclic olefin wt % 7 7 7 based resin B1 Modified cyclic olefin wt % 7based resin B2 Modified cyclic olefin wt % 14 based resin B3 Olefinicelastomer C1 wt % 24 24 24 15 Olefinic elastomer C2 wt % 24 Modifiedpolyolefin D1 wt % 6 6 6 Modified polyolefin D2 wt % 6 15 (A + B)/(C +D) wt ratio 70/30 70/30 70/30 70/30 70/30 A/B wt ratio 90/10 80/20 90/1090/10 90/10 C/D wt ratio 80/20 80/20 80/20 80/20 50/50 Characteristicsof composition Charpy impact strength kJ/m² 16.2 20.7 13.9 15.5 22.0Surface flaking off of Visual ◯ ◯ ◯ ◯ ◯ molding evaluation Cross cuttape test Number of 100 100 100 100 100 remaining grids

Examples 13 to 15

The results shown in Table 5 were obtained by making constitutions shownin Table 5, and performing the molding and the evaluation as is the casewith Example 1. TABLE 5 Example Unit 13 14 15 Constitution ofcomposition Cyclic olefin based resin A2 wt % 63 Cyclic olefin basedresin A3 wt % 63 Cyclic olefin based resin A4 wt % 63 Modified cyclicolefin based wt % 7 resin B1 Modified cyclic olefin based wt % 7 resinB4 Modified cyclic olefin based wt % 7 resin B5 Olefinic elastomer C1 wt% 24 24 24 Modified polyolefin D1 wt % 6 6 6 (A + B)/(C + D) wt ratio70/30 70/30 70/30 A/B wt ratio 90/10 90/10 90/10 C/D wt ratio 80/2080/20 80/20 Characteristics of composition Charpy impact strength kJ/m²21.5 18.1 23.0 Surface flaking off of molding Visual evaluation ◯ ◯ ◯Cross cut tape test Number of 100 100 100 remaining grids

As is obvious from Examples and Comparative Examples described above, itwas possible to remarkably improve the impact resistance of the moldingof the cyclic olefin based resin composition and further completelyeliminate the flaking of the molding surface by combining the modifiedolefin based resin (B), the olefinic elastomer (C), and the modifiedpolyolefin (D) with the cyclic olefin based resin (A).

Industrial Applicability

According to the present invention, a molding of a cyclic olefin basedresin composition which is excellent in impact resistance, resistance toflaking off, and the like is obtained.

1. A cyclic olefin based resin composition comprising: a cyclic olefinbased resin (A); a modified cyclic olefin based resin (B) prepared bygrafting and/or copolymerizing an unsaturated carboxylic acid or anunsaturated carboxylic acid anhydride to the cyclic olefin based resin(A) an olefinic elastomer (C); and a modified polyolefin (D) having anepoxy group, wherein a weight ratio A/B of the component A to thecomponent B is in a range of 98/2 to 2/98, a weight ratio C/D of thecomponent C to the component D is in a range of 98/2 to 2/98, and aratio (A+B)/(C+D) of a total weight of the component A and the componentB to a total weight of the component C and the component D is in a rangeof 95/5 to 50/50.
 2. The cyclic olefin based resin composition accordingto claim 1, wherein the component C is a copolymer of ethylene and anα-olefin.
 3. The cyclic olefin based resin composition according toclaim 1, wherein the component D is a copolymer of ethylene and glycidyl(meth)acrylate.
 4. The cyclic olefin based resin composition accordingto claim 1, wherein the component B is a modified cyclic olefin basedresin which is obtained by a cyclic olefin based resin being graftedwith (meth)acrylic acid or maleic anhydride.
 5. The cyclic olefin basedresin composition according to claim 1, wherein a cyclic olefin basedresin of the component A and a cyclic olefin based resin used as a baseresin prior to modification in the component B are independently acopolymer of ethylene and a cyclic olefin.
 6. A molding of cyclic olefinbased resin obtained by injection molding, compression molding,injection compression molding, extrusion, or blow molding of the cyclicolefin based resin composition according to claim 1.